DIAGNOSIS You’ve got a clog or an air lock in the automatic oiling system. The most common culprit is sawdust mixing with the oil and turning into a paste that blocks the small oil port in the bar pad or the bar’s own oil hole.
FIX First, with the bar and chain removed, run the saw at full throttle for 15-20 seconds while pointing the bar pad area at a piece of cardboard or bare ground. You should see a steady stream or drip of oil. If you do, the problem is your bar. Clean the bar’s oil hole (near the mounting end) with a thin wire or compressed air. If you don’t see oil from the saw, the oil passage in the saw itself is clogged. You’ll need to clean the oil port on the saw’s body with a wire.
IF THAT DIDN'T WORK Check for a faulty oil pump. A quick test: remove the bar and chain, hold the saw over a surface, and look into the oil port while pulling the trigger. You should see a pulse of oil synchronised with the motor sound. If there’s nothing, the pump might be dead. Also, ensure you’re using proper bar and chain oil, not motor oil or something too thick that congeals in the cold.
HEADS UP Never run the saw without bar oil, even for a “quick test.” A dry chain will destroy the bar rails and overheat the chain in seconds, leading to a very expensive repair. If you’re cleaning the oil system, it’s a good time to also clean out the bar groove and the oil tank cap vent.